Since you already tried connecting the printer, if you can see it in control panel, programs and features, remove the printer. If it is not there, then you'll have to manually remove the printer drivers.
Restart your computer.
Download the proper Vista Drivers, they're suppose to be backward compatible.
Install the proper drivers, you might have to install them using the compability mode.
Original poster, If you have solved your problem, can you please mark the correct thread(s) with your solution. Thanks
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#MicrosoftMVP - Windows Expert-Consumer April 1, 2012 to March 31, 2015
FYI..... Dell will not release any Win-7 drivers until they actually begin shipping Win-7 on their PC's.